A bad-boy actor (Josh Duhamel) out to rehab his image offers a date for charity. The winner, a little ol' gal from West Virginia named Rosalee (Kate Bosworth), turns out to be an accentless, self-possessed stunner. She never even needs a makeover. Oh, those celebrities and their selfless good works!

Bosworth's ("Blue Crush") ultrawhite teeth and chiseled cheekbones would not be so striking had "Win a Date With Tad Hamilton" been made in the broad comic vein of "Legally Blonde," director Robert Luketic's previous film. But the "Tad Hamilton" filmmakers, aiming to please teens and adults -- and judging from the shirtless shots of Duhamel, gay men of all ages -- have hedged their bets. Veering from throwback innocence to modern cynicism, the movie is neither a compelling underdog story nor an especially funny romantic comedy.

But it does have Duhamel. He's always a pleasure to watch, and not just because he benefits from the most flattering lighting since "The Mirror Has Two Faces." The TV heartthrob ("Vegas," "All My Children") brings surprising nuance to an ostensibly shallow character, a guy who's not really bad, just caught up in his own celebrity.

When Tad goes to West Virginia to bask in Rosalee's realness, he doesn't consider that she might be just another between-pictures diversion, like Kabbalah. His business people (Sean Hayes and Nathan Lane, the only actors here who seem to know they're in an Elvis movie) keep pointing out his flakiness, but Tad doesn't get it. Duhamel is an actor playing an actor who's not aware he's acting in his real life. That's a lot of layers for a lark like this.

Boswell has trouble with Rosalee's down-home expressions, as if she's embarrassed to say the words, and with her character's tongue-tied awkwardness around Tad. A young woman this polished and good-looking, whether from West Virginia or West Covina, would certainly know how to behave around guys. Yet Rosalee is supposed to be a 22-year-old innocent who lives with her dad and hangs out with her two co-workers from the Piggly Wiggly.

Bosworth has less chemistry with Duhamel than she does with Topher Grace, who plays a co-worker and childhood friend secretly in love with her. The romantic triangle quickly hits a roadblock, however, in Grace's character. The likable beanpole from "That '70s Show" does what he can, but this guy is a pill. Immature and sarcastic, he won't reveal his feelings to Rosalee, but he will make snide remarks about the movie star, and by extension, Rosalee's judgment. Tad always seems the better choice.

Ginnifer Goodwin ("Mona Lisa Smile") brings effervescence to her role as Rosalee's other friend, despite a disturbing character shift. In an early scene, she and Rosalee watch Tad onscreen in a cheesy World War II romance. "I wonder what he's doing right now?" Rosalee asks dreamily. "He's probably at church," answers the Goodwin character, as if it's really 1943. A couple of scenes later, however, the pal is propositioning Tad with some rather blue language. Something's missing here. Like a transitional scene.

"Tad Hamilton" has fun with the idea of celebrity invading a small town. The folks buzz over Tad's arrival with the same fervor that might accompany a Louisiana pop star's quickie marriage to a local boy. Gary Cole ("Office Space"), the unrivaled deadpan movie comedian, plays Rosalie's father, who at first seems unruffled by Tad's arrival. Then we see that Dad's trying to play the cool Hollywood insider, wearing a "Project Greenlight" T-shirt and quoting net grosses. A shot of Cole reading Julia Phillips' "You'll Never Eat Lunch in This Town Again" won't mean a thing to teens, but it will please Hollywoodphiles of a certain age.